What Is Ashwagandha?
Ashwagandha (Withania somnifera) is a traditional herb commonly marketed as an adaptogen, with the strongest evidence around stress-related outcomes, some support for sleep, and more limited evidence for performance-related benefits. It is thought to help the body manage stress by influencing the HPA axis (hypothalamic-pituitary-adrenal system).
Always consult with a healthcare professional before starting ashwagandha, especially if you have medical conditions or take medications.
What the Research Shows
Ashwagandha has been studied in multiple short-term human trials, though many are small. Here are the areas where the evidence looks most promising.
Stress & Anxiety
Several small trials suggest standardized extracts in the 300-600mg/day range may help reduce self-reported stress, with some studies also reporting lower cortisol. This is the best-supported use case, though study sizes are often small.
Sleep Quality
Some small trials suggest standardized extracts may improve sleep quality over several weeks. If sleep is your main goal, many people prefer taking it in the evening.
Athletic Performance
Some trials suggest possible benefits for strength and testosterone, but the evidence is limited and not consistent enough to treat ashwagandha as a guaranteed performance supplement.
Safe Dosage Guidelines
Weeks 1-2: Start Low
300mg once daily with food (morning). Monitor effects and tolerance before increasing.
Weeks 3-4: Add Evening Dose
300mg twice daily (morning and evening with meals). Total: 600mg/day.
Weeks 5-8: Maintain
Continue 300-600mg daily based on your response. This is when full benefits develop.
Week 9+: Consider a Break
Because long-term safety data is limited, some practitioners suggest taking 2-4 weeks off. This is a cautious strategy, not a proven requirement.
Look for standardized extracts like KSM-66 or Sensoril with third-party testing. These have the most research backing and consistent potency. Standardized extracts are better studied and usually easier to dose consistently than generic root powder products.
Safety & Side Effects
Short-Term Safety Looks Reasonable
- Generally well-tolerated at 300-600mg daily in trials up to 12 weeks
- Mild side effects typically resolve on their own
Possible Side Effects
- Nausea or stomach upset
- Drowsiness (especially initially)
- Diarrhea or headache
- Rare but reported: cases of liver injury - stop use and seek medical advice if you develop jaundice, dark urine, or persistent nausea
Pregnant/breastfeeding women, autoimmune conditions, thyroid disorders, hormone-sensitive conditions, those on blood pressure/diabetes/sedative medications, and anyone with upcoming surgery (stop 2 weeks prior).
Common Mistakes to Avoid
Expecting Instant Results
Benefits develop over 4-8 weeks. Don't give up after one week - adaptogens work gradually.
Taking Too Much
More isn't better. Stick to the best-studied range (300-600mg daily). Higher doses increase side effect risk without clear added benefit.
Buying Cheap Supplements
Choose standardized extracts such as KSM-66 or Sensoril with third-party testing when possible. Generic powders have inconsistent potency.
Long-Term Use: What Research Says
Most ashwagandha studies run 8-12 weeks. Longer-term data is limited, but here's what we know:
- Up to 12 weeks: The best-studied window. Most trials showing benefits for stress and sleep fall within this range.
- 3-6 months: Limited data. Some practitioners suggest periodic breaks, but this is a cautious practice, not an established rule.
- Beyond 6 months: No controlled safety data exists. If you choose to continue, periodic check-ins with a healthcare provider are reasonable.
When to stop: Discontinue and consult a doctor if you experience thyroid changes (ashwagandha can increase thyroid hormones), persistent GI issues, or if you're starting new medications. Ashwagandha may interact with thyroid drugs, sedatives, and immunosuppressants.
A common approach: 8 weeks on → 2-4 weeks off → reassess. This gives your body periodic breaks and helps you judge whether the supplement is still providing noticeable benefit. If you notice no difference after stopping, you may not need it.
Ashwagandha has reasonable evidence for stress reduction and some support for sleep. Performance claims are less convincing. If you try it, start with 300mg daily of a quality extract, give it at least 4-8 weeks, and consider periodic breaks. Supplements support good habits - they don't replace them.
Sources & References
- Chandrasekhar K, Kapoor J, Anishetty S. (2012). "A Prospective, Randomized Double-Blind, Placebo-Controlled Study of Safety and Efficacy of a High-Concentration Full-Spectrum Extract of Ashwagandha Root in Reducing Stress and Anxiety in Adults." Indian J Psychol Med, 34(3): 255-262. PubMed
- Pratte MA, Nanavati KB, Young V, Morley CP. (2014). "An Alternative Treatment for Anxiety: A Systematic Review of Human Trial Results Reported for the Ayurvedic Herb Ashwagandha (Withania somnifera)." J Altern Complement Med, 20(12): 901-908. PubMed
- Langade D, Kanchi S, Salve J, Debnath K, Ambegaokar D. (2019). "Efficacy and Safety of Ashwagandha (Withania somnifera) Root Extract in Insomnia and Anxiety: A Double-blind, Randomized, Placebo-controlled Study." Cureus, 11(9): e5797. PubMed